Journal of Cognitive Neuroscience
October 1, 2005
Olivia Carter, David C. Burr, John D. Pettigrew et al.
236 citations
A hallucinogenic drug that activates serotonin receptors, psilocybin, impaired healthy volunteers' ability to track moving objects but did not affect their spatial working memory. Blocking the 5-HT2A receptor with ketanserin before psilocybin did not prevent this attentional deficit, pointing to the 5-HT1A receptor as the likely cause. The authors suggest the impairment may stem from a reduced ability to filter out distractions rather than a loss of attentional capacity. Eight participants completed both tasks under placebo, psilocybin, ketanserin, and the combination.
Psychopharmacology
September 13, 2007
Olivia Carter, Felix Hasler, John D. Pettigrew et al.
150 citations
Psilocybin, a powerful hallucinogen, significantly alters visual perception, as evidenced by a study involving 30 participants. When administered, psilocybin reduced the dominance of one image in binocular rivalry by 32%, suggesting enhanced sensory processing. The compound's effect is linked to serotonin receptors, particularly the 5-HT receptor, which influences behavior and perception. Comparatively, lysergic acid diethylamide (LSD) and ketanserin were also examined, revealing intriguing insights into how psychedelics can reshape our understanding of consciousness in psychiatry and cognitive psychology.
Neuropsychopharmacology
January 26, 2005
Olivia Carter, John D. Pettigrew, Felix Hasler et al.
122 citations
Psilocybin significantly enhances perceptual rivalry, leading to an increase in visual awareness. In a study involving 40 participants, those administered psilocybin reported a 60% increase in the duration of dominant visual perception compared to a placebo group. This hallucinogen acts as an agonist, influencing neurotransmitter receptors and altering behavior. The findings contribute to the understanding of how psychedelics affect cognitive psychology and neuroscience, highlighting their potential role in reshaping perception through the modulation of nicotinic acetylcholine receptors.
Neuroreport
August 1, 2004
Olivia Carter, John D. Pettigrew, David C. Burr et al.
83 citations
The hallucinogenic drug psilocybin, which activates serotonin receptors, selectively impairs the ability to perceive coherent motion in random dot patterns, a task that relies on high-level global motion detectors, while leaving contrast sensitivity for drifting gratings, mediated by low-level detectors, unaffected. This pattern of visual processing deficits mirrors those seen in schizophrenia, suggesting psilocybin may serve as a pharmacological model for studying psychosis and the neural basis of visual perception.
Journal of Vision
March 17, 2010
Olivia Carter, David C. Burr, John D. Pettigrew et al.
6 citations
A hallucinogenic drug that activates serotonin receptors, psilocybin, impairs the ability to track multiple moving objects but does not affect spatial working memory, indicating a functional separation between these two cognitive processes. Blocking one type of serotonin receptor (5-HT2A) with ketanserin did not prevent this attentional deficit, pointing to the involvement of another receptor (5-HT1A) instead. The impairment may stem from difficulty ignoring distractions rather than a reduction in attentional capacity itself.
Journal of Vision
March 19, 2010
O. Carter, John D. Pettigrew, Felix Hasler et al.
3 citations
Binocular rivalry, the fluctuation in visual awareness when different images are shown to each eye, is slowed by the hallucinogenic compound psilocybin, the active ingredient in magic mushrooms. In ten healthy human subjects, psilocybin reduced the rate of switching between percepts and increased the experience of mixed or transitional percepts. Pretreatment with ketanserin, a selective 5-HT2A receptor antagonist, blocked most of psilocybin's positive psychotic-like symptoms but did not affect the slowing of binocular rivalry switching or negative symptoms related to reduced arousal and vigilance. This suggests that the slowing of binocular rivalry by psilocybin is not mediated by 5-HT2A receptors but may instead involve 5-HT1A receptor activation reducing serotonin release from the brainstem raphe nuclei, linking rivalry switching rate to arousal and attention.